Anker HDMI Cable 8K@60Hz, Ultra HD 4K@120Hz HDMI Cord,48 Gbps Certified Ultra High-Speed,Compatible with PlayStation 5,Xbox,Samsung TVs,and More (6FT)

HDMI 2.1 is pretty finicky, I had issues with multiple reputable brands cables, I finally settled on these from Anker and haven't had a single issues with them.

https://a.co/d/02Aah6ES I have so many HDMI cables laying around but this was a special occasion worth buying a new one for lol

In my experience, it's always the cable. I have 2x C2s and both have Xboxes attached. Xbox Series consoles and LG OLED both support full bandwidth 48Gbps HDMI 2.1 spec, so you need a high-quality cable to get full color depth 4k@120hz with HDR and VRR enabled without issues. I even had issues with the cable included with the Xbox and went through a handful of reputable brands and continued to have random signal loss issues and the green screen issue. These cables from Anker are the only HDMI 2.1 cables that have worked flawlessly for me.